Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Whole Foods Market (WFM) were looking rotten to investors today, falling as much as 22% after a disappointing second-quarter earnings report. 

So what: The organic grocer missed expectations on all three counts as increased competition seems to be taking a bite out of Whole Foods' growth. Revenue in the quarter increased 9.7% to $3.32 billion, a bit short of estimates at $3.34 billion, as same-store sales grew 4.5%, a respectable clip, but slower than expected. Profits were flat as food costs increased, dropping its operating margin 50 basis points to 7%. On a per-share basis, the company made $0.38, missing estimates of $0.41. Management also dialed back its own guidance, now forecasting 10.5%-11% revenue growth, and earnings per share of $1.52-$1.56, down from $1.58-$1.65. Wall Street had projected EPS of $1.61 for the year.

Now what: This morning, several analysts cut their ratings on the supermarket chain as Wall Street appears to have lost faith in the stock. Even the Whole Foods earnings call was brutal as analysts lambasted management for not having more of a plan for countering rising competition other than lowering prices. Co-CEO John Mackey admitted that "Competition is more intense now than we've possibly ever experienced," but the company is still growing, both organically and through new stores, and today's drop seems mostly valuation-based rather than a reflection of the company's overall health. The rest of the year won't be easy for Whole Foods, but shares finally look reasonably priced after today's fall.